Piano



M y 2, 1950 c. F. STEIN 2,505,806

PIANO Filed Feb. 5, 1947 6 Sheets-Sheet 1 IN VEN TOR.

May 2, 1950 c. F. STEM 2,505,806

PIANO Filed Feb. 5, 1947 6 Sheets-Sheet 2 INVENTOR. Charle gj 'edemtlo fiam C. F. STElN May 2, 1950 PIANO 6 Sheets-Sheet 3 Filed Feb. 5, 1947 INVENTOR. Charleslfiederie/a SZQLn,

C. F. STEIN May 2, 1950 PIANO Filed Feb. 5, 1947 6 Sheets-Shae; 4

v INVENTOR. Charlesfiederzc/zfizm May 2, 1950 c. F. STEIN 2,505,806

PIANO 6 Sheets-Sheet 5 Filed Feb. 5, 1947 E I INVENTOR. Charlesfieafierici 527297,,

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Patented May 2, 1959 UNITED ST watt PATENT OFFICE PIANO Application February 5, 1947, Serial No. 726,696

21 Claims. 1

This invention relates generally to pianos and l ore particularly to a small piano which is of com pact and lightweight construction and which lends itself to various furniture designs and also portable applications.

In prior piano constructions, two piano types have been commonly accepted, these types being generally called grand and "upright pianos. Grand pianos, while making a very pleasing and desirable appearance, are necessarily quite large and, therefore, are suitable only for large rooms and concert halls where a considerable amount of space is available. Upright pianos, while requiring a relatively small amount of space, have generally been clumsy in appearance, and although reduced size and spinet and console styling have been used to improve the appearance, the resulting structures have still been relatively large and heavy. Further, such upright pianos have been of such design that they must be placed against a wall of a room to thereby limit the possible arrangement of the furniture in the room.

As previously stated, various attempts have been made to reduce the size and weight of pianos but such attempts have not been entirely satisfactory because of the massive frame required to support the piano strings and resist the force caused by the tension thereof. Also the piano actions are relatively complicated mechanical systems and they must be properly positioned with reference ,to the piano keys and strings so that the desired movements result. This has generally required a considerable amount of space for the action and has, therefore, limited the design of such prior piano structures.

It is, therefore, an object of the present invention to provide a small piano which is of compact and lightweight construction.

It is a further object of this invention to provide a compact operating structure for a piano which is adaptable to various cabinet styling and is suitable for portable use.

It is another object of this invention to provide a piano action for use in a piano having horizontally positioned strings which is of simple and improved construction.

A still further object of this invention is to provide a, piano including a compact horizontal operating unit which is adapted to have cases of various types interchangeably applied thereto.

A feature of this invention is the provision of a horizontal string chassis having a piano key and action assembly supported thereon in which the string chassis and the key and action assembly are substantially coextensive.

A further feature of this invention is the provision of a single frame member on which piano strings and a sounding board are mounted and on which a piano key and action assembly are supported, with said frame member having recesses in which said sounding board is positioned and in which said key and action assembly is partially positioned so that a horizontal unit of relatively small height is provided.

Another feature of this invention is the provision of a piano key and action assembly for use with a piano having horizontally positioned strings in which the keys include extensions cooperating With the hammers to cause a downward. striking action thereof and springs are provided on the keys for causing return of the hammers to their normal positions.

Another feature of this invention is the provision of a small complete piano operating structure adapted to be horizontally positioned when in use which includes provisions for securing a piano case thereto so that cases of various types may be interchangeably applied to the operating uni Further objects, features and advantages will be apparent from a consideration of the following description taken in connection with the accompanying drawings in which:

Fig. l is a perspective view of a complete piano in accordance with the invention;

Fig. 2 illustrates the piano of Fig. 1 with the case closed and the legs removed;

Fig, 3 is a perspective view of the piano operating structure;

Fig. 4 is a detail view of an action support bracket and hammer rest;

Figs. 5 and 6 illustrate the operation of the piano key and action assembly in accordance with the invention;

Fig. 7 shows a modified spring suitable for use on the key in the combination shown in Figs. 5 and 6;

Fig. 8 is a top view illustrating the string chassis of the piano with the piano action in place;

Fig. 9 is a cross-sectional view illustrating the asoasoe FE 9 string chassis with the piano key and action assembly supported thereon;

Fig. is an exploded view illustrating the manner of applying a case to the piano operating structure;

Fig. 11 is a bottom view of the piano operating structure;

Fig. 12 is a detail view showing the means for securing the key slip;

Fig. 13 is a view showing details of the kneeoperated pedals;

Fig. 14 illustrates the piano in a case suitable for portable use; and

Fig. 15 illustrates the portable piano in oper ating position on a table.

In practicing my invention I provide a complete piano operating structure including a single metal frame member of generally rectangular shape and having recesses on either side thereof. A sounding board and pin block are secured within the recesses on one side of the frame and are positioned entirely within the confines of the frame. Piano strings are provided on the other side of the frame and a piano key and action assembly is also supported on this side of the frame for actuation of the strings. The key and action assembly extend partially within the recess in the frame and is positioned entirely within the rectangular confines of the frame being substantially coextensive therewith. This results in an operating structure having a minimum over-all size as the frame and key and action assembly are coextensive and of a minimum depth. Sufficient strength for supporting the piano strings is obtained by providing a peripheral flange and reinforcing ribs on the metal frame member. The key and action assembly in accordance with the invention includes a plurality of keys and hammers 50 arranged that an extension on a key cooperates with a projection on the butt of a hammer to cause the hammer to strike downwardly and engage a string when the key is operated. A spring is provided on the end of the key engaging the projection on the hammer butt to cause the hammer to be restored to its normal position. The action also includes a damper operatively connected with the hammer butt to be released when the hammer operates. The operating structure includes projecting brackets by which a knock-down piano case can be applied to the operating structure. Cases having various Well known furniture styles as well as cases adapted for portable use can be interchangeably applied to the operating structure.

Referring now more particularly to the drawings, Fig. 1 illustrates a piano in accordance with the invention in which the compact horizontal operating structure is positioned in a desk-type case. The case includes a main body portion which is supported by legs 2!. A lyre assembly 22 is supported from the case. The case includes the usual music desk 2 and a folding top panel 25 adapted to completely enclose the piano keys. In Fig. 2 the main portion of the case 28 is shown with the legs 25 and lyre 22 removed and the top panel closed. Removal of the legs permits easy handling of the piano, and the resulting structure can be supported on a table or other supporting means and forms a completely playable unit.

Referring now to Figs. 3 to 9, inclusive, the operating structure of the piano is disclosed as including a metal frame member Bil having a central web portion 3! and a peripheral flange 32 (Figs. 8 and 9). The web portion 3! is disposed substantially centrally of the flange 32 and in- 75 tion.

a cludes ribs 33 thereon to reinforce the frame at the points where the stresses therein caused by the piano strings are greatest. The frame is preferably constructed of an aluminum or magnesium. alloy such as Duralumin or Dowmetal which has a high tensile strength and is very light in weight. By using a frame made of such material a complete piano in accordance with the invention will weigh only approximately 80 pounds. Referring to Fig. 9, it is seen that a sounding board is supported on the frame 30 on one side of the web portion 3!, t e sounding board and supporting rims and 3G therefor being disposed entirely within the recess formed by the peripheral flange 32. It is noted that at the back of the frame (left side of Fig. 9) a flange 31 is provided on the frame 33 offset from the extreme edge of the frame so that a recess is formed in which a pin block 36 is positioned. Pins 39 extend through openings til in the web portion 3| of the frame into the pin block 38 and are secured therein in the usual manner. Projections ii are provided on the web 35 which together with the pins 39 form means for stretching the piano strings Bridges 43 are provided on the sounding board for engaging the strings :22.

Referring now to the piano key and action assembly, Figs. 3 and 8 show the piano action supported on the frame 30. The action includes a fixed rail structure supported by brackets 5| which are supported on the web portion SI of the frame member. The brackets support a hamrner rail 52, a damper rail 53, and a hammer rest as. Figs. 5 and 6 show the details of the piano action and illustrate the manner in which the action operates. The action includes a plurality of 5 3 having head portions 5? and butt portions fill pivotally mounted on supports 59 which are secured to the hammer rail 52. The butt portion includes a projection (iii having a screw 6! adjustably positioned therein and a felt 52 secured thereon for purposes to be presently explained. A damper 53, including a head portion 5% normally bearing against a string G2, is pivotally mounted to rail 53 by hinge 65. A spring 56 is secured to the hinge to hold the damper against the string. For the purpose of raising the damper when a string is actuated by a hammer, the damper is connected to the hammer butt 53 by a flexible cord 61 secured to the hammer butt and to hook 63 in the damper.

The keys '55 of the piano key and action assembly are supported on a key frame if which is secured to the metal frame it by Wooden mounting members l2 as shown in Fig. 9. The members "i2 are fastened to the flange 32 of the frame by any suitable means such as screws iii. The key frame supports the individual keys in the usual manner and includes pins i l for guiding the key. Each of the keys includes, at the rear end thereof, an extension i l adapted to cooperate with the projection on the hammer butt 53, a felt 15 being provided on the extension for engaging the head of the screw iii in the hammer butt. A spring 6f; is secured to the key it] by a screw Bl, the spring having a portion 82 which engages the projection ti: on the hammer butt. A second screv. 83 is provided for adjusting the tension of the spring 86.

Referring now to the operation of the piano key and action assembly, reference in particular is made to 5 and 6 wherein Fig. 5 shows the key and action in the normal position and Fig. 6 shows the key and action in the operative posi- As is apparent from the drawings, operation of the key causes the hammer 56 to be rotated in a counter-clockwise direction due to engagement of the screw 6! by felt T5 of the key. Although as shown in Fig. 6, the key does not move the hammer sufficiently for the head 5? thereof to touch the string 42, the momentum of the hammer will cause the head to continue until the string 42 is engaged. In order for this desired operation to take place, the spring 80 must be sufficiently flexible so that the portion 82 of the spring will permit the projection 6t of the hammer to continue its motion until the head 51 strikes the string. As the string 42 is tightly stretched, the hammer head 5? will bounce away therefrom and portion 82 of the spring will then exert sufiicient pressure on the projection til of the hammer butt to hold this projection against the extension M of the key and prevent the bouncing action to continue so that the hammer again strikes the string. When the key it) is released, the spring 80 by exerting pressure on the projection 56 of the hammer butt will cause the hammer to be raised to the normal position as shown in Fig. 5 and the engagement of the screw SI of the hammer and the felt E5 of the key will also cause the key to be raised to its normal position. It is apparent from Figs. 5 and 6 that the spring is flexed more in the actuated position so that it will tend to restore the key and action to the normal position.

In Fig. '7 there is illustrated a modified spring 98 which is fully equivalent to the spring 8i] of Figs. 5 and 6. The spring 98 is secured to the key it by a screw 9! and includes a portion 92 engaging the projection 68 of the hammer butt at substantially the same position as portion 82 of spring 80 engages the hammer butt in Figs. 5 and 6. A second screw 93 is provided in the key which may be adjusted to control the tension applied by the portion 92 of the spring on the hammer butt extension 60.

As is apparent from a consideration of Figs. 5 and 6, movement of the hammer by the key causes the damper 63 to be lifted from the string. As the hammer rotates the butt portion thereof rises and the cord 61 lifts the damper. Although the weight of the damper may be sufficient to restore it to the normal position engaging the string, a spring as shown by 66 may be provided to insure that the damper rests securely on the string. The hook 68 on the damper, to which the flexible cord 5'! is secured, is made of resilient material so that it may be bent to thereby change the cooperative relation between the damper and hammer as required when adjusting the piano action.

Referring specifically to Fig. 9, it is to be pointed out that the sounding board 34 and pin block 38 extend entirely within the recess formed in the frame 3t and that the key and action assembly extends to a certain extent within the recess on the other side of the frame. An operating structure is thereby provided having a very small vertical dimension, the width of the peripheral flange being less than 4 inches and the over-all vertical dimension of the unit being approximately 7 inches. It is also apparent from Figs. 3, 8 and 9 that the piano key and action assembly is positioned entirely within the space defined by the rectangular frame member and substantially covers the entire area defined by the frame mem ber. This results in minimum amount of waste space and provides a unit which is very small compared with prior piano operating structures. In operating units which have been constructed 6 and which include 64 keys, the depth of the unit is only 22 inches and the width is 36 inches. It is obvious that pianos having any number of keys up to the full 88 note key board could be provided by making the operating structure slightly longer. The compact arrangement of the keys and string chassis permits mounting of the operating unit in a case as shown in Figs. 1 and 10 in which the keyboard is positioned in the usual manner and there is enough room under the unit so that a person playing the piano can sit comfortably at the piano. As such a case presents an attractive piece of furniture when viewed from any angle, it is possible to place such a piano in a room in various ways not possible with former upright and spinet styles.

Fig. 10 illustrates the manner in which a knockdown case of a design such as in Fig. 1 can be applied to the operating structure. The operating structure is shown in Fig. 10 having brackets I0! extending therefrom to which various members of the case can be secured. These brackets llil are secured around the edge of the operating structure being fastened either to the rim 36 of the sounding board or to the pin block 38 as shown in Figs. 9 and 11. The piano case includes side members 532, a back member I33 and a front member iii-i all of which are secured to the operating structure by the brackets ill I. The brackets have holes through which screws may be inserted to fasten the members thereto. After the sides are positioned in place the key blocks H15 may be secured to the operating structure, being screwed or otherwise secured to the portions of the key frame which extend beyond the keys. Thereafter the shelf W5 which supports the music desk 24 is put in place being screwed to members Hi7 provided on the sides M2. The top panel 25 can now be secured in place being fastened to the back member by hinges W8. A key slip N39 is adapted to be secured to the key frame 'H of the operating structure by screws ill! provided therein. Slotted members [4 are provided on the key slip which engage the heads of the screws III] to hold the key slip in place as shown in Fig. 12. This completes the main portion of the case and provides a unit as shown in Fig. 2 which can be used without legs on any suitable supporting structure.

When a self-supporting piano unit is desired, the legs 2i may be used to support the operating structure. The legs have lag screws I ll secured in the top thereof adapted to engage the pin block and the corner braces of the sounding board. In Fig. 11, holes H2 are shown in the pin block for receiving the screws of the two back legs and holes H3 are shown in the corner blocks of the sounding board for receiving the screws of the front legs.

A supporting structure for mounting the lyre on the operating unit is provided and is shown in Fig. 13. This structure includes a pair of frame members 923 anchored at the ends thereof to the rim 3% of the sounding board. A supporting plate l2l is secured to the frame members and is adapted to have the lyre 22 secured thereto. The lyre (Fig. ll) includes a mounting plate E22 having a pair of pins I23 therein adapted to be positioned in openings [2d in the supporting plate l2i for properly positioning the lyre with respect to the operating unit. The mounting plate E22 also includes a pair of holes E25 through which screws E26 are inserted, the screws being secured in holes 52! in the supporting plate I21 to fasten the mounting plate thereto. By these means the lyre is securely fastened to the piano operating structure.

s saw T .e lyre itself is of generally standard construction including two pedals I35? and ESI which are pivotally supported in the base portion it?! of the lyre and which actuate rods E33 and I34. These rods extend through openings I35 in the mounting plate I22 and continue through openings 636 in the supporting plate 52! (Fig. 10) to operate a lever system which transmits the movement of the pedals to the piano action. The base portion 32 of the lyre is supported on the mounting plate i122 by a pair of legs l3! and a pair of braces it.

When usin the operating structure of the pione without the legs and lyre in place thereon, a lever system is provided for controlling the expression of the action including arms adapted to be operated by the knees of the person playing. That is, one arm is provided for releasing the dampers for loud or forte playing and a second arm is provided for controlling the stroke of the hammer to provide soft or piano effects. This action is provided by the pedals in the usual piano construction. In the drawings, Fig. 9 shows a movable rail its positioned under the dampers 63 for raising them from the strings. The rail I56 has an actuating rod Iill attached thereto which extends through the frame and sounding board. Fig. l3 shows the rail i553 actuating rod 55; together with the lever system for actu ating the same. This lever system includes a centrally pivoted. lever 52 which is mounted on the supporting plate iii. The lever H52 includes end portions 555'; and lo l, the end i553 being in contact with rod EM, and the end 554 being in contact with a Zshaped crank let. The crank 555 is pivctally supported on the operating structure and includes an arm 555 which extends below the operating structure to be actuated by the .knee of the person playing the piano. It is obvious from a consideration of Fig. 13 that by operating the arm so that it turns in a counterclockwise direction, the end of the crank 555 which engages the lever E52 will cause the end lli l of the lever move downward and the end I53 to move upward. This upward movement is transmitted through rod 51 to the rail E58 to release the dampers from the strings.

A similar lever system is provided for moving the hammer rest to provide a shorter stroke of the hammer for soft playing. Fig. 4 illustrates the manner in which the hammer rest 5 is secured to the brackets 5!. A support is secured to the bracket 5i and includes slot into which a on the rest 5*!- projects. An operating rod Iiil is secured to the hammer rest and a spring M32 is provided for normally holding the rest in the position shown in solid lines. It is obvious that when the rest is in the position shown in dotted lines the hammers have a shorter stroke and accordin ly do not hit the strings with as much force. Therefore holding the rest in the lower position against the tension of spring i 32 results in softer tones from the strings. The mechanism for operatin the rod tel is shown in Figs. 11 and 13 as comprising a lever E53 which is pivotally mounted on an e:-:- tension Hi l secured to a frame member i22 As shown in Fig. 11 this lever extends to the side of the piano where it is connected to rod Ifiii. The lever includes an end :55 adapted to be engaged by the rod I3 5 and a projection i 56 adapted to be engaged by a crank Nil. The crank I6l is generally similar to the crank i555 and includes an arm I58 adapted to extend below the operating structure to be engaged by the knee of a person playing the piano. The other end of the crank includes a right angle portion 159 adapted to engage the projection 566 on the lever I When the arm its is moved in a clockwise direction, the portion ESQ causes the lever I63 to move to pull the hammer rest down.

As shown in the dotted positions in Figs. 11 and 13, the cranks I55 and It! can be rotated to a position so that the arms 556 and E68 are completely out of the way. Recesses l5? are provided in the rim 36 of the sounding board into which the arms drop and clips I58 are provided for holding the cranks tilt and it? in this position. It is, therefore, seen that the lever system provides an operating structure which is complete without the use of the lyre 22. The cranks of the lever system can be moved out of the way when not in use and the lovers and H33 cooperate with the operating rods of the lyre to transmit the movement of the rods to the piano action.

When the lyre 22 is in position with the mounting plate I22 thereof secured to the supporting plate l2l on the operating unit, the operating rods M3 and 53:3 of the lyre are used to actuate the levers E52 and As is apparent in Fig. 13, the rods i3 3 and lll are positioned in openings I55 in the plate lEi when the lyre is socured thereto. The rod i353 engages the of the lever so that as the pedal ltd is depressed and the rod ifit raised, the end E53 oi the lever and actuating rod Iill will also be raised and the rail will raise the dampers from the strings. The rod i343 engages the lever so that as the pedal Ilil is depressed and the rod lil l the rod will be pulled down causing the hammer rest to move down and the stroke of the hammers to be shortened. When the lyre is in place, the cranks and i6"! can be moved to their out of the way position and held in th position by the clips Thus, the cranks not interfere with the operation of the love. 01' the pedals and actuating rods.

Figs. 14 and 15 illustrate the provision of operating structure of the piano in a case .3 adapted for portable use. In Fig. 14 the is shown closed as it would be when the piano was being carried. As previously stated, the en tire piano weighs approximately pounds, and the over-all size is approximately 22 inches by 36 inches by '7 inches deep so that the piano in this form would be easily portable. Fig. 15 shows the piano supported on a small table ill, the table being illustrated in dot-dash lines. The portable case illl includes a double hinged panel includin members and which wh n opened furnishes access to the keys to permit playing the piano. C or similar means ll' l are provided for holding the panel in a position whereby it can be used as a music desk. Slots I75 are provided in a bottom surface of the case in which the action controlling arms and I63 are positioned when the piano is being carried, the arms being held therein by any suitable clamp means. When. the piano is positioned for playing as in .15, the arms are pivot d to the position shown so that they can be engaged by the knees of the person playing the r- --o. The frame structure of the piano and the action 5% is generally shown dotted lines to indicate the position of the operating structure of the piano within the portable case 576. It is beli ved apparent fr in the foregoing that a readily portable piano is provided which is adapted to be supported on any available means and is in playing condition without any further assembly or adjustment of parts.

From the above description it is seen that I have provided a knock-down piano including an operating unit which is complete in itself and completely playable independent of a casing or supporting structure therefor. The compact arrangement of the frame and the mounting of the sounding board, strings and piano key and action assembly thereto provides a unit which is adaptable to various furniture designs not heretofore possible for a piano. The shallow construction of the string chassis permits the chassis to extend under the keyboard when it is mounted at the normal height and still allows sufficient room for a person to sit comfortably at the keyboard. The resulting operating unit is small and lightweight permitting the unit to be easily handled and a piano incorporating the unit to be easily moved from room to room as is desired. The complete piano embodying the improved piano unit may be of various attractive designs and does not include the usual limitation of upright pianos that one side thereof is unattractive and must be placed against a wall.

The operating structure is complete in itself and can be completely adjusted and then crated for shipment and storage as required. Due to the compact form of the operating unit a very small amount of space is required for shipping and storage thereof. When the piano is sold, a case of the desired design can be very rapidly applied thereto by a piano dealer without readjusting the action. This permits the dealer to keep a relatively few pianos in stock as it is possible to apply various case designs to any operating unit.

While I have described certain embodiments of my invention which are considered illustrative thereof, it is apparent that various changes and modifications can be made in the structure without departing from the intended scope of my invention as defined in the appended claims.

I claim:

1. A small horizontal piano comprising a single horizontally positioned frame member having recesses on the top and bottom sides thereof, a sounding board mounted on said frame member in said recess on said bottom side thereof, piano strings supported by said frame member in said recess on said top side thereof, an action supported on said top side of said frame member including hammers positioned with respect to said strings for actuation thereof, and a key frame supported on said top side of said frame member including keys extending parallel to said frame, each of said hammers including a butt having a projection thereon, each of said keys including a rear portion having an extension thereon adapted to engage said projection on said hammer butt and a spring secured to said key and engaging said hammer butt for holding said projection against said extension, said action and said key frame extending horizontally entirely Within the area defined by said frame and substantially completely covering said area.

2. A piano in accordance with claim 1 in which said keys and said action are so constructed and arranged that removal of said keys from said piano does not affect adjustment of said action.

3. In a piano having horizontally positioned strings, a piano action and key assembly for actuating said strings comprising fixed rail and key frame structure. a down striking hammer iii including a butt which is pivotally mounted on said rail structure and a head adapted to strike a string, said hammer butt having a projection thereon, a piano key supported on said key frame structure, said piano key having an integral rear extension positioned in cooperative engagement with said projection on said hammer, a spring positioned on said key adjacent said rear extension and engaging said projection for holding said projection against said extension, and adjustable means for securing said spring to said key whereby the tension in said spring can be adjusted.

A piano key and action assembly comprising a fixed rail structure, a hammer including a butt pivotally mounted on said rail structure and having a projection thereon, a key frame, a piano key supported on said hey frame and having an integral rear extension positioned in cooperative engagement with said projection, a spring, supporting means for mounting said spring on said key adjacent said extension with one end of said spring engaging said hammer butt, said spring tending to hold said extension against said projection so that said key and said hammer are held in position for operation thereof, said supporting means including an adjusting screw for varying the tension in said spring so that the pressure exerted by said spring on said hammer butt can be varied.

5. A piano key and action assembly in accordance with claim 4 including a damper mounted on said rail structure and means interconnecting said damper and said hammer for causing movement of said damper when said hammer is actuated by said key.

6. A small horizontal piano comprising a string chassis, a piano key and action assembly, and means on said string chassis for securing a case thereto for styling the piano, said string chassis including a single frame member having recesses on the top and bottom sides thereof, a sounding board supported in said recess on said bottom side of said frame member, piano strings supported in said recess on said top side of said frame member, said piano key and action assembly being supported on said frame member in operative position with respect to said strings.

7. A piano in accordance with claim 6 in which the piano key and action assembly is positioned directly above said frame member and extends entirely within the area defined by said frame member.

8. A compact operating unit for a horizontal piano comprising a single metal frame member including a peripheral flange and a web portion disposed centrally within said flange, a sounding board secured to said frame member on one side thereof and positioned within the recess formed by said peripheral flange, piano strings and a piano key and action assembly supported on said frame member on the other side thereof, said assembly extending vertically partially within the recess formed by said peripheral flange and exte iding horizontally entirely within the area defined by said flange. 9. An operating unit for a piano in accordance with claim 8 in. which said piano key and action assembly covers substantially the entire area of said frame.

10. An operating unit for a piano in accordance with claim 8 which forms in itself a complete playable piano structure and which includes provisions for securing a case thereto for styling said piano.

11. A compactpiano operating unit comprisingia single horizontally positioned. rectangular metal frame member including a web portion anda peripheral flange defining recesses on the top and bottom sides of said frame member, a sounding board secured to said frame member and positioned in the recess on the bottom side thereof, piano strings and a piano key and action assembly supported on said frame member on the top side thereof, said key and action assembly bein positioned partially within said top recess and extending entirely within the rectangular area defined by said peripheral flange and substantially covering said entire rectangular area.

12. A compact piano operating unit which forms itself a complete playable unit and which includes provisions for securing supporting legs and an enclosing case thereto, said operating unit comprising a single metal frame member including a web portion and a peripheral flange defining recesses on either side of said frame member, a sounding board and a pin block secured to said frame member and positioned in the recess on one side thereof, niano'strings and a piano key and action assembly supported on said frame member on the other side thereof and extending at least partially within the recess on said other side, and means on said sounding board and pin blocks for securing a piano case and supporting legs to said operating unit.

13. A knock-down piano comprising an operating unit adapted to be horizontally positioned and including a string chassis having'a single frame member, a piano key and action assembly removably supported on said frame member, said key and action assembly being positioned above said string chassis and entirely within the rectangular area defined thereby, said operating unit including provisions thereon for securing a case thereto, and a case including legs for supporting said o erating unit and a plurality of members ada ted to enclose said operating unit, said case members bein adapted to be assembled to each other when they are secured to said operating unit.

34. A piano comprising an operating unit which forms in itself a complete playable unit independent of a case and su porting means therefor, said operating unit including a string chassis, a piano key and action assembly supported by said chassis and superimposed thereon, said action including movable rail means for modifying the expression thereof, and a lever system secured to said string chassis for operating said movable rail means and including retractable actuating arms extending below said chassis.

15. A piano comprising an operating unit which forms in itself a complete playable unit and which includes provisions thereon for securing supporting legs and a lyre thereto, said operating unit including a string chassis, a piano key and action assembly supported on said chassis, movable rail means for modifying the expression of said action, and a lever system secured .to said string chassis for operating said movable rail. means, said lever system being operable independently of said lyre, said lyre'including pedals and mechanical means adapted to be connected to said lever system when said legs and said lyre are secured to said'operating unit so that movement of said pedals is transmitted to said movable rail means.

16.. Apiano in accordance with claim 15 in which said lever system includes actuating arms which are adapted to be positioned below said operating unit for operation bythe kneesof a person playing the unit, said arms being adapted to be retracted into said operating unit when said lyre is secured thereto, and said lever system is operated by said mechanical means.

1?. A knock-down piano comprising an operating unit which forms in itself a complete playable unit and which includes provisions thereon for securing a case thereto, and a case adapted to be secured to said operating unit including supporting legs, members adapted to enclose said operating unit, and a lyre, said operating unit including a string chassis, a piano key and action assembly supported by said chassis and superimposed thereon, said action including movable rail means for modifying the expression thereof, said string chassis including provisions thereon for receiving said legs, and means on said string chassis for removably securing said enclosing members and said lyre thereto, said lyre including pedals and mechanical means adapted to be operetively connected to said movable rail means when said case is applied to said operating unit so hat movement of said pedals is transmitted to said movable rail means.

18. In a piano having horizontally positioned strings, a piano action and key assembly for actuating such strings comprising fixed rail and key frame structures, a down striking hammer including a butt which is pivotally mounted on said rail structure and a head adapted to strike a string, said hammer butt having a projection thereon, a piano key supported on said key frame structure, said piano key having an integralrear extension positioned in cooperative engagement with said projection on said hammer, a spring supported on said key adjacent said rear extension and engaging said projection for holding said projection against said extension, a damper mounted on said rail structure, a second spring secured to said rail structure and adapted to hold said damper against a string, and flexible means secured to said hammer butt and said damper and arranged .to lift sa d damper oif said string when said hammer is actuated by said key.

19. A horizontal piano comprising a string chassis, a key and action assembly positioned above said string chassis, and a case enclosing said string chassis and key and action asesmbly, said key and action assembly including piano keys and hammers extending in end-to-end relation from the front to the back of said string chassis, spring means for controlling the movement of said keys and hammers, and means for adjusting the tension of said s ring means, said case including a music rack positioned across said keys adjacent the rear end theerof and a hinged top cover, said adjusting means being positioned back of said music rack so that they are available adjustment by raising said hinged cover.

0. A portable piano carrying case for a compact completely playable piano operating unit which includes keys for operating the unit and a retractable arm for modifying the. expression of the unit,,said carrying case completely enclosing said operating unit and including means for carrying the same, said carrying case having a hinged panel for providing excess to said keys and an. opening therein through which said arm may extend to. a position outside said case for operation by a person playing the piano.

21. A portable piano carrying case for housing a compact piano operating unit which is completely playable when supported horizontally on a table or the like and which includes keys for operating the unit and a retractable arm for modifying the expression of the unit, said portable carrying case completely enclosing said operating unit and including means for carrying the same, said carrying case having a, hinged panel on one side thereof which may be opened to provide access to said keys by a person playing the piano and an opening in the opposite side thereof through which said arm may extend to a position below said case for operation by the knees of the person playing the piano.

CHARLES FREDERICK STEIN.

REFERENCES CITED The following references are of record in the 15 file of this patent:

Number Number Great Britain Apr. 9, 1925 

